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Title: Platelet-derived growth factor (PDGF) stimulates glycogen synthase activity in 3T3 cells

Hormonal regulation of glycogen synthase, an enzyme that can be phosphorylated on multiple sites, is often associated with changes in its phosphorylation state. Enzyme activation is conventionally monitored by determining the synthase activity ratio ((activity in the absence of glucose 6-P)/(activity in the presence of glucose 6-P)). Insulin causes an activation of glycogen synthase with a concomitant decrease in its phosphate content. In a previous report, the authors showed that epidermal growth factor (EGF) increases the glycogen synthase activity ratio in Swiss 3T3 cells. The time and dose-dependency of this response was similar to that of insulin. Their recent results indicate that PDGF also stimulates glycogen synthase activity. Enzyme activation was maximal after 30 min. of incubation with PDGF; the time course observed was very similar to that with insulin and EGF. At 1 ng/ml (0.03nM), PDGF caused a maximal stimulation of 4-fold in synthase activity ratio. Half-maximal stimulation was observed at 0.2 ng/ml (6 pM). The time course of changes in enzyme activity ratio closely followed that of /sup 125/I-PDGF binding. The authors data suggest that PDGF, as well as EFG and insulin, may be important in regulating glycogen synthesis through phosphorylation/dephosphorylation mechanisms.
Authors:
; ; ;
Publication Date:
OSTI Identifier:
6899102
Report Number(s):
CONF-8606151-
Journal ID: CODEN: FEPRA; TRN: 87-006987
Resource Type:
Conference
Resource Relation:
Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States); Journal Volume: 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
Research Org:
Univ. of Washington, Seattle
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; LIGASES; ENZYME ACTIVITY; ENZYME REACTIVATION; PHOSPHORYLATION; PROTEINS; BIOCHEMICAL REACTION KINETICS; FIBROBLASTS; GLYCOGEN; IODINE 125; PEPTIDE HORMONES; TRACER TECHNIQUES; ANIMAL CELLS; BETA DECAY RADIOISOTOPES; CARBOHYDRATES; CHEMICAL REACTIONS; CONNECTIVE TISSUE CELLS; DAYS LIVING RADIOISOTOPES; ELECTRON CAPTURE RADIOISOTOPES; ENZYMES; HORMONES; INTERMEDIATE MASS NUCLEI; IODINE ISOTOPES; ISOTOPE APPLICATIONS; ISOTOPES; KINETICS; NUCLEI; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; POLYSACCHARIDES; RADIOISOTOPES; REACTION KINETICS; SACCHARIDES; SOMATIC CELLS 550201* -- Biochemistry-- Tracer Techniques